Masses of compact (neutron) stars with distinguished cores

TL;DR

This paper investigates how the core properties of neutron stars, including potential exotic matter, influence their mass-radius relationship, broadening the range of possible star configurations.

Contribution

It introduces a parameterized core model that accounts for various matter compositions, extending the understanding of neutron star mass-radius relations beyond standard assumptions.

Findings

Core mass significantly affects mass-radius relations.

Inclusion of exotic matter broadens possible neutron star configurations.

Core parameters allow modeling of diverse matter compositions.

Abstract

The impact of the core mass on the compact/neutron-star mass-radius relation is studied. Besides the mass, the core is parameterized by its radius and surface pressure, which supports the outside one-component Standard Model (SM) matter. The core may accommodate SM matter with unspecified (or poorly known) equation-of-state or several components, e.g. consisting of admixtures of Dark Matter and/or Mirror World matter etc. beyond the SM. Thus, the admissible range of masses and radii of compact stars can be considerably extended.